Increase the max command line length for RestartJob.
Increase the max command line length for RestartJob.

1024 became too short for Chrome to switch to the guest mode.

BUG=chromium-os:143005
TEST=confirmed that the guest mode worked with --disable-accelerated-2d-canvas added on Link

Change-Id: Id512cddfedca58c6aa958d31e4a5e0a8e938fa57
Reviewed-on: https://gerrit.chromium.org/gerrit/30609
Tested-by: Satoru Takabayashi <59864788db41f0f5af51640995670e228eeb7e4d@chromium.org>
Reviewed-by: Daniel Erat <69d56254d3d393520d06e9838c23c147a5fee7d9@chromium.org>
Commit-Ready: Satoru Takabayashi <59864788db41f0f5af51640995670e228eeb7e4d@chromium.org>

chadversary/chromiumos.platform.login_manager,chadversary/chromiumos.platform.login_manager,chadversary/chromiumos.platform.login_manager